The objectives of the proposed research are the following: (a) to develop an experimental force measuring probe that will generate information on deformation characteristics of gingival tissues, (b) to measure gingival elastance in normal and inflamed states and determine the optimal probe diameter to discriminate between them, (c) to determine the probe location in healthy and inflamed gingival sulci with different pressures, and (d) to assess the contributions of the gingival corium to the pressure-displacement characteristics obtained during probing. An electromechanical force-displacement probe will be developed that contains a force transducer, that is specially designed for small displacements and high sensitivity. Since the probe advances at a constant velocity, the output can be recorded as force vs. displacement. This experimental probe will be used to explore differences in the force vs. displacement curves between healthy and inflamed attached gingiva of nine Beagle dogs. Probe diameters of 0.20, 0.40, 0.60 and 0.80 mm. will be tested to determine the optimal diameters that will aid in the above discrimination. In addition, the probes will be luted to tooth surfaces at different pressures and disease states to determine locations of the probe relative to histological tooth and gingival structures. Finally in additional Beagle dogs, the contribution of connective tissue fibers of the gingiva to the formation of the curves produced by the experimental probe will be studied. The probe will be permitted to advance into the sulcus parallel to the tooth surface before and after incisions are made parallel to the tooth surfaces. Comparisons of the force-displacement curves before and after the experimental procedure will be performed.